| 摘要 |
PROBLEM TO BE SOLVED: To provide an on-board lighting device reducing the frequency of the light-out due to reduction in input voltage. SOLUTION: It is determined whether or not to charge a battery based on an AC component included in an input voltage Vin from the battery. When it is determined that the battery has charge, power output to an electric light source is stopped immediately when the voltage from the battery falls below a first minimum voltage Vb1. When it is determined that the battery does not have charge, however, power output to the electric light source is not stopped unless a duration time T1v where the input voltage Vin is lower than a second minimum voltage Vb2 lower than the first minimum voltage Vb1 continues for a predetermined drop determination time Tsh. Reduction in input voltage Vin is less likely to turn off the electric light source as compared to a case of always performing the operation to be performed when it is determined that the battery has the charge. COPYRIGHT: (C)2011,JPO&INPIT |
